Reaction of a polymerization-resistant 1,2-dithiolane with lithiated nitrogen heterocycles

✍ Scribed by Masato Tazaki; Toshihiko Hieda; Hironori Maeda; Shizuo Nagahama; Akinori Jyo

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 162 KB
• Volume: 9
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/(sici)1098-1071(1998)9:3<289::aid-hc2>3.0.co;2-5

✦ Synopsis

Nitrogen-containing five-membered heterocycles, N-methylpyrrole 2, N-methylpyrazole 4, N-methylimidazole 6, 4-methylthiazole 11, N-methylindole 14, benzothiazole 16, N-methylbenzimidazole 18, and benzoxazole 20 were lithiated with BuLi and LDA in THF and reacted with the polymerization-resistant 1,2-dithiolane 1. All of the corresponding lithioheterocycles cleaved the S-S bond of the 1,2-dithiolane 1 to give the ring-opened products in line with the carbanion mechanism proposed for the enzyme-reductive acylations of lipoic acid. The ring-opened products 8, 9, 13, 22, and 23 were isolated in good yields and high purity. The ring-opened products from benzothiazole and N-methylbenzimidazole were decomposed by the action of excess lithioheterocycles. The lithiobenzoxazole was less reactive than the other lithioheterocycles.